1) Technical Field of the Invention
The present invention relates to a sliding door system, and in particular relates to the sliding door system used for any equipment and facility such as an elevator system and an automatic sliding door system in a building and automobile.
2) Description of Related Arts
There have been disclosed various elevator systems each equipped with a safety installation for preventing any members such as clothes from being drawn into a small gap defined between a slide door and a fixed wall adjacent to the door when the door opens a doorway into or out of an elevator cage. Among others, the Japanese Patent Publication No. 63-66084 (A) discloses such a safety system, in which a vertical recess is formed at a vertically extending corner edge between one vertical wall defining the doorway and the other vertical wall adjacent to the opening/closing door. A pair of a light emitter and receiver are provided at a top and bottom portions of the vertical recess in order to detect any members such as clothes positioned near the gap between the opening/closing door and the adjacent fixed wall and, if detected, to prohibit the opening operation of the door.
Also, the Japanese Patent Publication No. 11-310375 (A) discloses an another safety installation, which includes a pair of a light emitter and receiver positioned on a vertical line within a small gap or space defined between the opening/closing door and the adjacent fixed wall for the detection of any members which has been drawn into the space.
The safety installations, however, have respective drawbacks. For example, according to the former safety installation, dust or foreign matters are retained at the bottom of the vertical recess, which results in a false detection of the member. On the other hand, the latter safety installation is capable of detecting any members already existing in the gap, but it is incapable of preventing any members from being drawn into the gap.
Also, other safety installations of the elevator system are proposed in a commonly assigned and co-pending U.S. patent application Ser. No. 10/094,993 filed on Mar. 12, 2002, which is incorporated herein in its entirety by reference.